List jar contents:

jar -t filename.jar

Extract a named file:

jar -x filename.jar (name)

Extract all:

jar -x filename.jar

See http://java.sun.com/j2se/1.4.2/docs/tooldocs/tools.html

Particularly the jar and javap tools.

HTH,
Carl.

In addition to using the jar commandline, if you're using an IDE (like Sun
One Studio, etc.), you can mount the jar file and expand it in a tree
structure to see all of it's classes, fields, method signatures, etc.
visually.

Hi,
The simple answer is yes. I do not know of a tool that will decompile the
classes from the jar (but it may be out there). If you unzip or extract
using jar -x so you have class files, then you can use jad to decompile.
Also Jedit has a plugin that will use Jode, within the Jedit IDE.
You could build a tool that would read the jar (see java.util.jar) and then
stream the stuff to Jode, and for all I know this may exist as a plugin to
Jedit. Jode is written in Java with source, Jad is C.

This will work on 99% of the stuff out there. A few people have encrypted
the class files, and provide a class loader that knows how to decrypt the
files. Having written one of these encryption tools I would point out they
are not that secure.Just note that by using Jode/Jad you may be breaking a
copyright or other legal agreements, so don't publish the code you obtain
this way, it almost always is illegal. There are a few books that discuss
this, if you just want to hack then "Covert Java" is pretty interesting and
while written on a basic level the author (Alex Kalinosky) does address some
very interesting problems, but not for the OO crowd.

Howie

As someone said, jad is good. I would use winzip & extract all the
class files into some directory and then run jad from dos on them.

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